Check Engine Light- Gas Cap Problem

Hi! I drive a 2006 Corolla that has less than 30,000 miles. About a week ago, my check engine light came on so the first thing I did was to see if my gas cap was loose. It seemed like it wasn't loose but to be sure, I retightened my gas cap with 5 clicks at the end. When I went to start my car the following the day, the light was gone. The car was running fine but a couple days ago, the light came back on again so I retightened my gas cap and the light was gone. When I went to drive my car later, the light came back on again and when I retighten my gas cap, the light would be gone and this has been happening for the past couple of days. The car seems to be running fine. I do notice that when the check engine light comes on, I feel a little jolt coming from my car. I believe the jolt is coming from my exhaust because when I hit the gas, air is suppose to come out of my exhaust but it hesitates before it lets the air out. This jolt disappears when the light is gone.

I have gone to a Kragen and AutoZone in hopes of getting my code checked but apparently the stores in the area that I live in no longer check codes anymore. I get the feeling that if I went to a dealership to get it checked, they will give me some crap about how it is my fault for not tightening the gas cap and I will be billed for it since it is not covered in the warranty even though it is a reoccurring problem.

I was wondering if anyone has any advice on what I should do or knows the symptoms of a gas related check engine light or knows an inexpensive place for me to get my code checked. Thanks for taking the time to read this!

Given how often that CEL came on for you - I would invest in a inexpensive OBD-II CAN protocol compliant scanner. Right now, you can probably pick one up for less than $60 - dealership will charge you atleast $85 for a diagnostic service fee. The scanner will pay for itself the first time you pull the code.

Right now - without knowing what the code is for certain - not sure if it is a gas cap related issue or not. You could just replace the gas cap as an alternative - the rubber gasket back there doesn't last forever. A shop will be able to pressure test the cap - but again, the diagnostic charge will probably cost more than a new cap and scanner combined.

You should NOT be able to feel any drivability change when the CEL comes on. If you do - then there is a very good chance that it is not related to the gas cap being loose. CELs will automatically go out after a certain period of time, number of starts and stops, etc. You only need to tighten it to a few clicks - extra clicks generally will not tighten the cap any more.

At this point, I would suggest buying a scanner. Save yourself having to drive to a shop or dealership to pull codes. Don't have to buy a brand new one - might be able to get one really cheap on eBay or Craigslist. Hit regular retail outlest as well Sears, Wal*Mart, etc. - might have them cheap.

Thanks for the response fishexpo101. I called a Midas service center earlier today and they told me that they were willing to find out what the code is for free but anything else that has to do with that code, I will be charged $100. I plan on heading there tomorrow.

Hello and Welcome to the forums.

Given how often that CEL came on for you - I would invest in a inexpensive OBD-II CAN protocol compliant scanner. Right now, you can probably pick one up for less than $60 - dealership will charge you atleast $85 for a diagnostic service fee. The scanner will pay for itself the first time you pull the code.

Right now - without knowing what the code is for certain - not sure if it is a gas cap related issue or not. You could just replace the gas cap as an alternative - the rubber gasket back there doesn't last forever. A shop will be able to pressure test the cap - but again, the diagnostic charge will probably cost more than a new cap and scanner combined.

You should NOT be able to feel any drivability change when the CEL comes on. If you do - then there is a very good chance that it is not related to the gas cap being loose. CELs will automatically go out after a certain period of time, number of starts and stops, etc. You only need to tighten it to a few clicks - extra clicks generally will not tighten the cap any more.

At this point, I would suggest buying a scanner. Save yourself having to drive to a shop or dealership to pull codes. Don't have to buy a brand new one - might be able to get one really cheap on eBay or Craigslist. Hit regular retail outlest as well Sears, Wal*Mart, etc. - might have them cheap.

Today I went to get my code checked and was told that there was something wrong with the computer system in my car. I then took it to a Toyota service center where they told me the same thing. Another code that Toyota found was for the gas cap which I had already corrected. Since my car is still under warranty, I won't have to pay for anything. It's going to be a couple days before I get it fixed since they have to order the part but I'm feeling relief.

I got my car fixed. The code that came up was P2716 which is a known problem for 2005 and 2006 Corolla and Matrix owners. I am not sure about the 2007. Apparently, there was a techinal service bulletin I was unaware of when I bought my car and was not told about. To this day, they haven't even sent me mail about this yet! Luckily, this is covered under the federal emissions part of the warranty, 8 years/ 80,000 miles. More info in the link below.

Thanks for the link. Yup, unfortunantely, dealerships are not required to inform owners of TSBs, as these are ongoing "fixes" that may or may not apply in all cases. These are made available to shops and dealerships that have TIS program - private owners can get this info as well, but through a monthly subscription program (Alldata, TIS, etc.).

With these ECMS, sometimes they spring the suspect CEL - sometimes they just flat out die before they get to that point. Luckily, you got the favored condition (suspect CEL + failure within the emissions warranty period). Best way to stay up to date on those are forums like this one and others. Recalls are the ones that the dealerships usually contact owners.